A broad range of human diseases, such as Alzheimer's disease, type II diabetes, Huntington's disease and the many prion-associated diseases, are associated with the aggregation of misfolded proteins. The misfolded proteins self-assemble into sticky plaque-like substances, termed amyloid. While it remains unclear how protein self-assembly of misfolded proteins leads to the development of each disease, recent studies have suggested that the formation of lower order protein aggregates (two to ten self-assembled proteins) leads to cellular toxicity and ultimately to the progression of each disease (1-3). While each disease is linked to different misfolded polypeptides (Ab and hyperphosphorylated Tau in Alzheimer's disease, Islet Amyloid Precursor Protein in type II diabetes and polyglutamine in Huntington's disease), the initial stages of amyloid formation appear to be similar. We propose to use a fluorescent screen to identify substances that inhibit the self-assembly of amyloid-forming proteins. In this screen, the gene for each amyloid-forming protein is genetically fused to the gene for enhanced green fluorescent protein (EGFP) (4, 5). When the amyloid-EGFP fusion proteins are expressed in E. coli the natural propensity of the amyloid proteins to aggregate precludes EGFP from folding and fluorescing. However, in the presence of substances that prevent amyloid aggregation, the fused EGFP can fold properly and fluoresce green (6). We propose to screen combinatorial peptide libraries, natural product extracts and synthetic small molecules to isolate and identify substances that inhibit amyloid formation and, therefore, show potential as therapeutic agents for preventing or slowing the progression of Alzheimer's disease, type II diabetes and Huntington's disease. PUBLIC HEALTH RELEVANCE: Diseases such as Alzheimer's, Huntington's and type II diabetes are associated with the self-assembly of misfolded proteins. We propose to screen peptides, extracts from natural product sources and synthetic molecule libraries to identify agents that inhibit amyloid formation. These experiments have the potential to discover new therapeutic agents for amyloid-based diseases.